DNA is the main type of genetic material found in a cell. In addition, it is found in the nucleus of the cell, so (D) is correct. DNA in the nucleus is used in replication (through mitosis and meiosis) via daughter cells to continue cell growth.
In humans, the maintenance of a stable internal temperature is a direct result of Homeostasis. Homeostasis is the ability of the body to maintain an equilibrium condition within it's internal environment even when dealing external changes. Homeostasis happens in human when there is an effort exerts by the body to regulate it's internal temperature around 98.6 degrees Fahrenheit. For example, during summer days we produce sweat for our body to cool off, and during winter we shiver for our body to produce heat.
The answer is concrete laundry trays.
This is because as concrete trays ages with timeit becomes coarse and rugged due to water, soap and detergents. Their smoothness gradually fades with time, thus this makes it not as good regarding to health wise standards of living.
6CO2 + 6H2O --> C6H12O6 + 6O2
carbon dioxide + water --> glucose + oxygen
The arrow indicates sunlight (energy).
:)